A seal assembly for a blowout preventer of a wellsite is provided. The blowout preventer includes a housing and at least one component operatively connectable to the housing. The housing has a bore and a channel therethrough. A tubular is positionable through the bore and engageable therein. The seal assembly includes a seal plate, a seal carrier, and at least one seal. The seal plate is operatively connectable between the housing and the at least one component of the blowout preventer, and has at least one seal groove extending therein. The seal carrier is disposable about a perimeter of the seal plate, has at least one carrier lip disposable in a seal groove(s), and has at least one seal receptacle. The seal is receivably positionable in the seal receptacle, and in sealing engagement with one of the housing, the component, and combinations thereof.